Don't get me wrong, I love having them around, and their bizarreness leads to a lot of hilarity, but they just think very differently than I do.
Case in point: I have noticed that when a friendlier cat come up to me, they rub their faces against my hand and pants and the chair I am sitting on and everything else in sight. My conclusion has always been that "awww, this kitty wants me to pet her face". That's not what's happening at all.
The cat is rubbing her scent on me, through scent glands around her mouth. Once she's rubbed her scent on me, she considers me "hers". Every time I wash my hands (pants, chair, etc), she feels she needs to reclaim me, to feel like "this is mine. I belong with this."
That seems to be one of the reasons cats like scratching things (like the couch), too. They also have scent glands on their paws and use their claws to rub their scent in (they doubly mark their territory by scratching: they also are visually altering the furniture to look like "theirs").
I guess it's better than spraying. :)